Winding mechanism for self-winding watches



July 21, 1953 M. P. HUGUENIN WINDING MECHANISM FOR SELF-WINDING WATCHES Filed Jan. 26, 1949 FIG. 2

UNITED STAT-E Patented July 21, 1953 s rArsur orrics Application January 26, 1949, Serial No. 72,857 In Switzerland June 10, 1948 1 Claim. (01. 58-82) The present invention relates to a winding mechanism for self-winding watches with a movable winding weight.

It is an object of the invention to provide a novel and efficient automatic winding mechanism for self-winding watches.

A further object of theinvention is to provide a winding mechanism of simple and rugged construction whereby the winding weight actuates the winder of the watch over the major part of its rotational movement.

According to the invention, the winding weight drives a cam having a periphery forming at its major part a curve of gradually increasing radius, the ends of which curve being connected by a short, steeply inclined slope, which cam cooperates with a cam follower actuating a ratchet wheel belonging to the winder of the watch.

These and other features and advantages of the novel winding mechanism according to the present invention will appear from the following description and claims in conjunction with the accompanying drawing, which illustrates by way of example an embodiment of the invention.

In the drawing:

Figure 1 shows a plan view of the winding mechanism of the watch from the side of the bridges.

Figure 2 shows a section along the lines II-II of Figure 1, portions being broken away for reasons of clearness.

The oscillating weight, designated as I, has a half circular disc-like form and is pivotally mounted and freely rotatable on a pin 2 carried on a bridge 3 of the watch. Coaxially with the weight l, a cam' l is pivotally mounted on a cylindrical bush 23 at one end provided with a flange by means of which the bush is also fastened to the bridge 3. The periphery of the cam 4 presents for the greater part a curve of gradually increasing radius, the two ends of this curve designated as 5a and 51), respectively, being connected by a short slope 5c of steep inclination (Figure 1). The profile of the periphery of the cam 4 has a triangular form as shown in Figure 2, corresponding to a groove of triangular crosssection in a roller l2 lying against the periphery of the cam. The cam 4 is coupled by means of a free wheel arrangement to the winding weight I in such a way that it is taken along by the weight rotating in the direction of the arrow 6, but is retained when the weight moves in the opposite direction. To this effect the cam is provided on both of its flat faces with a ring of upright ratchet teeth 1 and 8, respectively, the teeth 1 cooperating with a corresponding flat upright spring 9 mounted on the weight l, and the teeth 8 cooperating with a, corresponding flat upright spring [0 mounted on the flange of the bush 23 fastenedto the-bridge 3. The spring 9 engaging one of the teeth 'l' drives the cam 4 on rotation of'the weight, iin the direction of the arrow 6, the spring l0 meanwhile; skipping over the teeth li; the weight l turning in the reverse direction, the cam 4 is retained by the spring l0 en a n o of the te -:8.

The roller l2 cooperating with the cam 4 is pivotally carried by an arm lla of a pivotally mounted lever l l, which roller is held in contact with the cam by means of a spring l3 acting on a second arm llb of the lever ll.

The lever H has a hole l8 of a non-circular elongated cross-section, the eccentrical part of said hole lying opposite the arm llb. Through this hole passes a hollow shaft l9 fastened to the barrel bridge 20 of the watch and serving as a pivot for the lever ll. Rotatably mounted on the same shaft I?! are a ratchet wheel l5 and a pinion l6 rigidly connected to the ratchet wheel, the ratchet wheel l5 cooperating with a pawl 22 permitting it to turn but in one direction, and the pinion l6 engaging the barrel wheel I! of the watch. The lever l l and the moving body l5, l6 are axially kept in place by a screw 24 passing through the hollow shaft is and resting with its head on the lever l l.

The arm I lb of the lever l I has the form of a circle segment and is provided with an internal toothing l4 of inwardly pointing ratchet teeth lying in the same plane as the ratchet teeth of wheel l5 and cooperating therewith. The elongated hole It permits a radial displacement of the lever H with respect to the shaft l9 in a direction along the axis of the arm llb in such a way that the toothing l4 may skip over the teeth of the ratchet wheel l5 when the lever is turned contrary to the direction of the arrow Zl The winding mechanism operates as follows:

When the winding weight l rotates in the direction of the arrow 6, for instance as a result of a movement of the wrist the watch is worn on, the spring 9, engaging one of the teeth I on the cam 4, rotates the cam in the same direction. The lever arm I lb pressing with its roller 22 against the periphery of the cam 4 is consequently moved outwardly in the direction of the arrow 2! and the lever ll is turned around its pivot l9 over a small angle, as the radius of the periphery of the cam 3 increases at the contact point of the roller l2 and the cam. The

toothing M of the lever arm llb engages the teeth of the ratchet wheel 15 and takes this wheel along, so that through the pinion l6 and the barrel wheel l1, winding takes place. When the end 522 of the curve of the cam periphery reaches the roller 12 (position as .shown in .Figure 1), the spring l3 moves the lever in the direction opposite to the arrow 2| as the roller rolls along the short slope 50. During this short reversal of the movement of the lever J l, the teeth [4 skip over the teeth of the ratchet wheel l5, the latter being retained by the pawl 22. As soon as the roller l2 encounters the point 5a of the cam periphery, winding of the watch is resumed.

When the weight rotates in the direction-opposite to that of the arrow 6, the cam 4 is not taken along, the spring 9 skipping over the teeth I of the cam. During this movement of the weight,

the cam is retained by the spring I0 engaging one 20 of the teeth 8.

As will be apparent from the above description, an advantage of the winding mechanism of the present invention forms the fact that winding occurs on the major part of the periphery of the cam 4 moving along the roller l2, the lever H being quickly returned to its initial position when the roller leaves the short, steep slope '50.

What I claim and desire to secure by Letters Patent is:

In a self-winding watch comprising a cam controlled by a winding weight, a swinging lever the oscillations of which are produced by said cam, a ratchet wheel belonging to the winder of the watch and mounted coaxially with said swinging lever, a toothed sector on said lever, coaxial with said ratchet wheel and carrying inwardly directed ratchet teeth intended to engage with said ratchet wheel, a double acting spring cooperating with said lever for applying it against said cam MARC PH. HUGUENIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,153,546 Camp Apr. 11, 1939 FOREIGN PATENTS Number Country Date 60 Great Britain Jan. 4, 1883 31,459 Germany May 18, 1885 

